Closed system drainage design

ABSTRACT

Means for eliminating the negative pressure problem in a closed urinary (or other) drainage system by shaping or conditioning the interior surface of the drainage tube to overcome differentially the surface tension of the liquid in the tube, permitting air to enter and release the column of liquid, such means comprising making the lumen of the tube noncircular (ridged or grooved), and, where needed. providing a slanting cut opening at the lower end of the tube.

United States Patent ["21 lnvcntor Vincent L. Vaillancourt Livingston.NJ.

[21 I Appl No 792.565

[22 Filed Jan. 21.1969

[45] Patented Sept. 14, 1971 173] Assignee C. R. Bard, Inc.

Murray Hill, NJ.

[54] CLOSED SYSTEM DRAINAGE DESIGN 7 Claims, 7 Drawing Figs.

[56] References Cited UNITED STATES PATENTS 1,596,754 8/1926 Moschelle128/350 3.428.046 2/1969 Remer et al. 128/349 1,928,992 10/1933 Clark etal. 128/349 2,749,913 6/1956 Wallace 128/295 3,190,290 6/1965 Alley eta1... 128/348 3,270,790 9/1966 Clark 128/275 3,332,422 7/1967 Jinkens eta1. 128/275 3,417,750 12/1968 Carson 128/349 3,429,314 2/1969 Ericson128/295 X 3,430,631 3/1969 Abramson 128/350 Primary ExaminerCharles FRosenbaum At!orneyW. Saxton Seward ABSTRACT: Means for eliminating thenegative pressure problem in a closed urinary (or other) drainage systemby shaping or conditioning the interior surface of the drainage tube toovercome differentially the surface tension of the liquid in the tube,permitting air to enter and release the column of liquid, such meanscomprising making the lumen of the tube noncircular (ridged or grooved),and, where needed. providing a slanting cut opening at the lower end ofthe tube.

PATENTEI] SIEPI 4m: 3.604.420

INVENTOR Vincent LVxiHam court BYhomWnlh-om ATTOR N EY-S CLOSED SYSTEMDRAINAGE DESIGN A major problem in the operation of a closed urinarydrainage system is the hand-up of the liquid column in the drainagetube, which tube normally extends generally downward from the level ofthe patient's bladder to a receptacle some distance lower. The weight ofsuch a column results in the development of negative pressure in thebladder, not only emptying it, but also tending to draw the bladder wallagainst the end of the catheter and even partly into the eyes thereof,with serious adverse effects on the patient.

Methods heretofore proposed to alleviate or eliminate this conditioninclude venting the system at a suitable point in its upper portion anduse of abnormally large diameter tubes. As for the latter a tube of morethan I l/32-inch ID. will release its liquid column if vigorously shakenand it is believed that tubing larger than one-half inch will allow freeflow of the liquid as air enters the outlet and bubbles up through thedescending liquid, but most closed systems actually use tubing in therange of 3/l6-inch to 9/32-inch I.D. and substitution of larger tubingis not considered practical or convenient.

The entry of air into the lower end of a small tube is prevented by thesurface tension of the liquid column at that point. It has beendiscovered that the provision of a tube having a noncircular lumen,i.e., longitudinally ridged or grooved, so increases the wettedperimeter of the tube lumen that the surface tension can no longer holdthe end of the liquid column together to prevent entry of air. As aresult the liquid will descent in discontinuous slugs or drops as airbubbles ascend, and the negative pressure, if any, developed in thebladder remains within tolerable limits.

Practical embodiments of the invention are shown in the accompanyingdrawings, wherein:

FIG. 1 represents an elevation of a complete closed urinary drainagesystem;

FIG. 2 represents an elevation of a drainage bag and holder having anordinary drop chamber;

FIG. 3 represents a detail vertical sectional view of the upper part ofthe drip chamber of FIG. 1, the vent being enlarged out of proportionfor illustrative purposes;

FIG. 4 represents a transverse section on the line IVIV of FIG. I;

FIG. 5 represents a section corresponding to FIG. 4 showing analternative form;

FIG. 6 represents a detail horizontal section on the line VI- VI of FIG.3 through the vent and cap only, and;

FIG. 7 represents a detail vertical section of the upper portion ofadrip chamber with straight-cut tube end.

Referring to the drawings, a urinary drainage system is shown ascomprising the normal elements of catheter 1, drainage tube 2, dripchamber 3 and collection receptacle 4, in the form a bedside bagsupported in any customary manner. With the catheterv installed in apatient the flow of liquid through the tube 2 would, in the case of aplain tube having an ID. less than one-half inch, create undesirablenegative pressure in the bladder due to the weight of the downwardlymoving liquid column. This is overcome in the present case by formingthe drainage tube 2 in a special configuration, as indicated in FIGS. 4and 5, the interior having longitudinally extending ridges or splines 5(FIG. 4) or grooves 6 (FIG. 5). It is found that the noncircular crosssection of the tube lumen has a disorienting effect on the surfacetension at the lower end of the liquid column, permitting air to bubbleup through the liquid and effectively counteracting the negativepressure at the upper end.

The commencement of such bubbling action can be assured by the provisionof a bevel tip 7 at the lower end of the drainage tube, within the dripchamber. If a liquid column (or slug of any length) reaches this pointsubstantially intact, it will be broken up immediately by the entry ofair at the upper portion ofthe bevel opening.

Air is permitted to enter the drip chamber (or leave it) through a vent8, shown as including a collar 9 projecting upward from the top of thechamber 3, a venthole 10 passing through said top, a small wad of cotton11, acting as a filter, and a cap 12 with inwardly projecting fins 13between which air may pass. The form of the recess within the collar 9permits easy insertion of the cotton filter.

Liquid enters the drip chamber from the tube 2 with a head which may beas much as two or three feet (plus pressure from the bladder) so thatthere is likely to be a rapid flow, whereas the head in the dripchamber, vented to atmosphere, is only the depth of the pool which maycollect in the drip chamber. The base 24 of the chamber must thereforebe substantially larger than the inlet; it is fitted with a wide fluttervalve 15 within the bag 4, designed to permit emptying of the dripchamber at a rate fast enough to prevent flooding.

The drip chamber 3, bag 4' outlet 14' and flutter valve 15, shown inFIG. 2 are substantially in scale for a nonvented drip chamber, incomparison to the enlarged drip chamber, outlet and flutter valve ofFIG. 1.

The flutter valve 15 physically closes off the drainage bag 4 from thedrip chamber 3 and the drainage tube 2 so that there is no open-air pathfor airborne bacteria to ascend from the bag into the drip chamber, tubeand eventually the patient. The drip chamber breaks the liquid path butno provisions have been made heretofore to break also the air path.

The cap 12 over the vent protects the cotton 11 from becoming wet in theevent that the patient takes the bag into a shower. If wetted, thecotton would close the vent.

In the alternative form of FIG. 7, the lower end 16 of the drainage tubeis shown as being cut straight across, without the bevel. While theprovision of a noncircular cross-sectional form in the tube lumen tendsto permit entry of air bubbles, even without the beveled end, morereliable operation can be achieved when the tube end is bevel cut. Infact, the provision of a beveled end on a tube of circular cross sectionwill ensure entry of air bubbles into the tube, particularly in thelarger sizes, e.g. 9/32-inch I.D., but the combination of the bevel withthe noncircular section gives the best assurance of satisfactoryoperation.

What I claim is:

l. A closed system for drainage of liquid from a body cavity comprisinga tubular conduit having a liquid inlet opening in the cavity and adownwardly extending section, a drip chamber, and a drainage receptaclein a position to receive liquid from said conduit, the lumen of at leastpart of the downwardly extending section being noncircular in crosssection, the lower end of said noncircular part of .the downwardlyextending section projecting into the drip chamber, and said lower end,being bevel cut.

2. A system according to claim I in which the air vent is constituted bya hole through the top of the drip chamber, a collar surrounding saidhole and a cap fitting over said collar with provision of an air passagebetween the collar and the cap.

3. A closed system for drainage of liquid from a body cavity comprisinga tubular conduit having a liquid inlet opening in the cavity and adownwardly extending section, a drip chamber, and a drainage receptaclein a position to receive liquid from said conduit, the lumen of at leastpart of the downwardly extending section being noncircular in crosssection, the lower end of said noncircular part of the downwardlyextending section projecting into the drip chamber, and the drip chamberbeing provided with a flutter valve on its outlet.

4. A closed system for drainage of liquid from a body cavity comprisinga tubular conduit having a liquid inlet opening in the cavity and adownwardly extending section, a drip chamber, and a drainage receptaclein a position to receive liquid from said conduit, the lumen of at leastpart of the downwardly extending section being noncircular in cross section, the lower end of said noncircular part of the downwardly extendingsection projecting into the drip chamber, the drip chamber beingprovided with an air vent, and the lower portion of the drip chamberbeing enlarged and provided with a wide-flaring flutter valve on itsoutlet.

5. A drip chamber for use in a body fluid drainage system comprising ahollow closed container, an inlet tube extending into the upper part ofthe container and terminating at a point below the container wallthrough which the tube passes, an outlet at the bottom of the containerthe cross-sectional area of said outlet being substantially larger thanthe cross-sectional area of the inlet tube and an air vent in the upperpart of the container at a level above the termination of the inlettube.

6. A drip chamber according to claim 5 in which the outlet is providedwith a flutter valve of a size sufficiently large to permit the flow offluid outward through the outlet at a rate at least equal to the rate offlow into the container through the inlet tube.

1. A closed system for drainage of liquid from a body cavity comprisinga tubular conduit having a liquid inlet opening in the cavity and adownwardly extending section, a drip chamber, and a drainage receptaclein a position to receive liquid from said conduit, the lumen of at leastpart of the downwardly extending section being noncircular in crosssection, the lower end of said noncircular part of the downwardlyextending section projecting into the drip cHamber, and said lower end,being bevel cut.
 2. A system according to claim 1 in which the air ventis constituted by a hole through the top of the drip chamber, a collarsurrounding said hole and a cap fitting over said collar with provisionof an air passage between the collar and the cap.
 3. A closed system fordrainage of liquid from a body cavity comprising a tubular conduithaving a liquid inlet opening in the cavity and a downwardly extendingsection, a drip chamber, and a drainage receptacle in a position toreceive liquid from said conduit, the lumen of at least part of thedownwardly extending section being noncircular in cross section, thelower end of said noncircular part of the downwardly extending sectionprojecting into the drip chamber, and the drip chamber being providedwith a flutter valve on its outlet.
 4. A closed system for drainage ofliquid from a body cavity comprising a tubular conduit having a liquidinlet opening in the cavity and a downwardly extending section, a dripchamber, and a drainage receptacle in a position to receive liquid fromsaid conduit, the lumen of at least part of the downwardly extendingsection being noncircular in cross section, the lower end of saidnoncircular part of the downwardly extending section projecting into thedrip chamber, the drip chamber being provided with an air vent, and thelower portion of the drip chamber being enlarged and provided with awide-flaring flutter valve on its outlet.
 5. A drip chamber for use in abody fluid drainage system comprising a hollow closed container, aninlet tube extending into the upper part of the container andterminating at a point below the container wall through which the tubepasses, an outlet at the bottom of the container the cross-sectionalarea of said outlet being substantially larger than the cross-sectionalarea of the inlet tube and an air vent in the upper part of thecontainer at a level above the termination of the inlet tube.
 6. A dripchamber according to claim 5 in which the outlet is provided with aflutter valve of a size sufficiently large to permit the flow of fluidoutward through the outlet at a rate at least equal to the rate of flowinto the container through the inlet tube.
 7. A drip chamber accordingto claim 5 in which the air vent includes a small hole through the wallof the container, a collar projecting from said wall around said hole,filtering material within said collar and a cap fitted over said collar,an air passage being provided between the collar and cap.